(Updates location of storm, number of power outages in Nova Scotia and New Brunswick)
By David Bailey
July 5 (Reuters) - Arthur weakened from hurricane force on Saturday and pelted parts of southeast Canada with heavy rain and strong winds, leaving 250,000 homes and businesses without power, as the storm swept away from New England.
Arthur weakened to a tropical storm on Saturday morning after having reached landfall on North Carolina's Outer Banks late on Thursday as a Category 2 hurricane, snarling plans for tourists at the start of the Fourth of July holiday weekend.
North Carolina reported only slight damage from the hurricane, which quickly traveled northeast.
Arthur, now a post-tropical storm was centered about 90 miles (146 km) southwest of Iles de la Madeleine on Saturday night after making a second landfall in Canada on Saturday afternoon.
The still intense storm, with maximum sustained winds of about 60 miles per hour (90 km per hour), was expected to head northeast across the Gulf of St. Lawrence and Newfoundland on Sunday before exiting into the North Atlantic, Environment Canada's Canadian Hurricane Centre said.
"Basically, it lost its tropical characteristics and has become more a wintertime-type low," said Daniel Brown, a senior hurricane specialist at the U.S. National Hurricane Center.
More than 122,000 customers in Nova Scotia and 140,000 in New Brunswick were left without power on Saturday night due to strong winds and heavy rain that were expected to continue over parts of southeastern Canada into Sunday.
Arthur was the first hurricane to hit the United States since Superstorm Sandy devastated New York and New Jersey in October 2012, causing an estimated $70 billion in damage.
In Maine, some communities reported power outages and trees down, but there were no injuries from Arthur, according to the National Weather Service, which received unofficial reports of more than 6 inches of rain (15 cm) in the eastern tip of the state.
"It's going to continue to wind down as we go through the afternoon hours," said Dustin Jordan, a weather service meteorologist in Caribou, Maine.
Arthur hit landfall with top sustained winds of 100 mph (160 kph), earning a Category 2 status on the five-step Saffir-Simpson scale. It weakened to a Category 1 as it moved northeast into colder waters of the Atlantic Ocean with 90-mph (145-kph) top sustained winds.
The storm lashed the popular Massachusetts resort island of Nantucket with powerful winds and heavy rain on Friday night.
In North Carolina, Arthur cut power to almost 20,000 homes and businesses, downed trees and cut off barrier islands from the mainland after making landfall on the state's Outer Banks.
The tourist haven of Ocracoke Island was without main power on Saturday, but a generator was providing power on a rotating basis and officials said power could be restored by late Sunday.
A highway connecting Hatteras Island to the mainland had been blocked, but has reopened. Permanent residents are being allowed back on Hatteras Island. (Reporting by David Bailey in Minneapolis; Additional reporting by Eric Martyn in Bedford, Nova Scotia, and Gene Cherry in North Carolina; Editing by Alex Dobuzinskis, Stephen Powell, Leslie Adler and Lisa Shumaker)